"For me he was not just a political colleague but a close friend whom I had first met when we were both students at Glasgow University.

"My sadness today is lifted only by many happy memories I shall always have of the fun times we shared.

"I am sure that this will be true of John's many friends today. My thoughts are with his partner David, his daughter Kirsty and the rest of his family."

East Dunbartonshire MP Jo Swinson said: "This is shocking news and my heart goes out to John's partner, family and friends. John was a skilful debater and effective leader of East Dunbartonshire Council.

"He dedicated decades of his life to public service, both in elected politics and at Glasgow City Council. This is a tragic loss."